With respect to a window installed in a residence with good airtightness such as in a collective housing like a condominium, there has been a problem of condensation collecting on the inside of the window especially on winter mornings, for example. The condensation can be effectively prevented by installing double-glazed windows providing a thermal insulation layer between two plate glasses.
Furthermore, so as to prevent a phenomenon called “cold draft”, that is, a flow of cold air onto a room floor of air cooled adjacent an inside surface of a glass in a cold season, a heat-generating glass has been increasingly employed, in which an electrically-conductive thin layer is formed on the plate glass to cause the electrically-conductive thin layer to generate heat. This type of the heat-generating glass is known, for example, as disclosed in Japanese Patent Application Laid-open Publication No. 2000-277243.
In the above document, a structure is described in which an electrically-conductive heat-generating layer on a surface of a translucent panel such as a plate glass and a pair of electrodes are provided by applying electrically-conductive paste to cover metal tape adhered to the heat-generating layer along opposing sides of the plate glass. To the electrodes elongated along the respective sides are connected lead wires for electrically connecting the electrodes with an external power supply.
For example, the electrically-conductive paste may be silver paste that is cured by heating through supplying hot air after application or being exposed to a far-infrared ray lamp to form the electrodes, each integrally including the metal tape. However, the above conventional curing method has problems in that time for curing is inevitably extended because the entire electrically-conductive paste as applied cannot be uniformly heated to be cured, which results in increase in energy loss. Thus, improvement of the conventional curing method has been desired in light of energy saving and reduction of manufacturing cost.
Further, in a collective housing such as a condominium, a number of heat-generating glass windows each having a heat-generating layer are often installed. In this case, when the heat-generating glasses are supplied with electric power at the same time, a problem sometimes occurs in that a large rush of electric current flows from a power supply to the heat-generating layer of each of the heat-generating windows and an overcurrent breaker operates to stop power supply at a peak of the rush current, causing significant downtime before power recovery. Moreover, there has been another problem in that the volume of wiring required for supplying electric power to a large number of heat-generating windows installed in each home from a power supply is increasing following expansion of the size of the housing where the heat-generating windows are installed, with a concomitant increase in the wiring cost and the cost for maintenance of the installed wiring.